Usefulness of Soluble Concentrations of Interleukin Family Member ST2 As Predictor of Mortality in Patients with Acutely Decompensated Heart Failure Relative to Left Ventricular Ejection Fraction

The aim of the present study was to determine whether the risk of mortality associated with the concentration of soluble ST2 (sST2) differs in patients with acutely decompensated heart failure with preserved ejection fraction (HFpEF) compared to patients with systolic heart failure. We prospectively enrolled 447 patients with acutely decompensated heart failure. Blood samples were collected at presentation to determine the sST2 concentration. HFpEF was defined as symptoms or signs of acutely decompensated heart failure and left ventricular ejection fraction of ≥50% on the echocardiogram. The patients were followed up for 1 year, and the vital status was obtained for all. The sST2 concentrations were greater in the patients with systolic heart failure (n = 250) than in those with HFpEF (n = 197) at 0.55 versus 0.38 ng/ml (p <0.001). Receiver operating characteristic curve analyses showed different cutoff point values for sST2 for the prediction of 1-year mortality in patients with HFpEF (>0.35 ng/ml) and systolic heart failure (>0.56 mg//ml). These cutoff points had similar prognostic accuracy (area under the curve of 0.69 vs 0.73; p >0.05). In the adjusted analyses that included amino terminal B-type natriuretic peptide concentrations, elevated sST2 concentrations were associated with a greater mortality risk in both populations (HFpEF, per ng/ml, hazard ratio 1.41, 95% confidence interval 1.14 to 1.76, p = 0.002; and systolic heart failure, per ng/ml, hazard ratio 1.20, 95% confidence interval 1.10 to 1.32, p <0.001). The determination of the sST2 concentration improved the clinical risk prediction compared to amino terminal B-type natriuretic peptide, as assessed by both the improved C-statistic and an improvement in the net reclassification index and integrated discrimination improvement analyses. In conclusion, in the present multicenter study, sST2 concentrations were lower in patients with HfpEF; however, sST2 remained an independent predictor of mortality, regardless of the left ventricular ejection fraction.